This investigation combines a clinical study with a study of normal phonation to obtain data relevant to the prediction of laryngeal dysfunction. This prediction or assessment is to be made from analyses of the recorded utterance and/or the laryngograph signal. Ultra high-speed laryngeal films exposed simultaneously with the speech and laryngograph signals will be used to confirm the predictions based on the acoustic and laryngographic analysis. We propose the measurement, analysis and parameterization of the vibratory patterns of vocal cord motion from the ultra high-speed laryngeal films using automated procedures already developed. This data will be correlated with the acoustic and laryngographic signal analysis results. Our objective is to determine and rank order the parameters from all three data sets which contribute most significantly to reproducing the sound of the original utterance. Our procedure will combine analysis and synthesis. We will use linear prediction modeling and other analysis techniques to extract parameters that are important to normal (and abnormal), natural sounding speech. Our hypothesis is that the vocal cord vibratory pattern is perhaps the major factor relating laryngeal function to the sound produced. We propose the development of a parametric model and theory of vocal cord motion and the assessment of the role this motion plays in speech production for clinical and normal populations.